Spacecraft/Environment Interactions

Catalog description

This course examines the effects on spacecraft design and operation, both short and long term, by the four aspects of the space environment: the neutral environment, the plasma environment, the radiation environment, and the micrometeoroid and orbital debris environment, both in near-Earth as well as interplanetary space. The neutral space environment includes the three regimes of rarefied gas dynamics; slip, transition, and free molecular flow, as determined by the Knudsen number; spacecraft surface degradation due to physical, chemical, and mechanical processes, and an introduction to the Direct Simulation Monte Carlo (DSMC) computational method for calculating rarefied flows. The calculation of spacecraft drag, lift, and pitching moments in free molecular flow is detailed. The plasma space environment in space is examined and the confinement of plasma via magnetic fields is derived. Spacecraft charging of both spacecraft bodies and solar cell arrays due to the plasma environment with the resultant damage due to arcing is analyzed. The effect of spacecraft grounding scheme, positive, negative, or floating, on spacecraft charging is examined. The sources of space radiation; trapped radiation belts (Van Allen belts), galactic cosmic rays (GCR), and solar proton events (SPE) and coronal mass ejections (CME); are quantified and the various types of radiation, high energy photons or particles, are covered. The effects of radiation on spacecraft materials, in particular solar cells and electronic components, and biological occupants such as humans, along with means of shielding against them are quantitatively examined. The space micrometeoroid and orbital debris environments are examined with a particular emphasis on the increasing population of orbital debris. Impact dynamics to calculate cratering and penetration distances and current methods such as the Whipple shield for protecting spacecraft from micrometeoroids and orbital debris are covered. Methods to prevent the formation of orbital debris as accepted by the international community are discussed.